From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Tue, 30 Sep 2025 08:08:34 +0000 (+0800)
Subject: crypto: zstd - Fix compression bug caused by truncation
X-Git-Tag: v6.17.2~6
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=15ea288e1dc8ee90d9a04bb197f22599240e42c4;p=thirdparty%2Fkernel%2Fstable.git

crypto: zstd - Fix compression bug caused by truncation

commit 81c1a15eb4a273eabedfcc28eb6afa4b50cb8a46 upstream.

Use size_t for the return value of zstd_compress_cctx as otherwise
negative errors will be truncated to a positive value.

Reported-by: Han Xu <han.xu@nxp.com>
Fixes: f5ad93ffb541 ("crypto: zstd - convert to acomp")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: David Sterba <dsterba@suse.com>
Tested-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/crypto/zstd.c b/crypto/zstd.c
index c2a19cb0879d6..ac318d333b684 100644
--- a/crypto/zstd.c
+++ b/crypto/zstd.c
@@ -83,7 +83,7 @@ static void zstd_exit(struct crypto_acomp *acomp_tfm)
 static int zstd_compress_one(struct acomp_req *req, struct zstd_ctx *ctx,
 			     const void *src, void *dst, unsigned int *dlen)
 {
-	unsigned int out_len;
+	size_t out_len;
 
 	ctx->cctx = zstd_init_cctx(ctx->wksp, ctx->wksp_size);
 	if (!ctx->cctx)